I have a confession to make. I don’t much like cities. In fact, as a kid I hated them.

Growing up in the suburbs of New Jersey a few turnpike exits away from Manhattan, I gravitated to the woods, streams, and fields of the Garden State instead of the concrete jungle that was home to my immigrant relatives. Nature made sense to me — it had a rhythm and reason I could understand.

None of this is surprising for a guy who ended up working in the conservation field. But somewhere along the way, I came to appreciate not just the appeal of cities (museums, people, and culture) but also their outsize role in affecting the planet’s future.

According to the United Nations, half the world’s population now lives in cities, and that proportion is expected to increase to more than two-thirds by 2050. If we are to solve our most pressing problems, from climate change to dwindling freshwater resources, we have to get it right in our urban centers. The challenges are immense, but so are the opportunities.

Today, cities are sprouting some of the most innovative green projects in the world, redefining a sustainable future for urban dwellers — and attracting travelers, too.

Here are just a few examples:

High-Rise Shrubbery in Milan

The world’s first vertical urban forest is rising above Italy’s largest industrial city. Bosco Verticale consists of double towers planted with some 700 trees, 5,000 shrubs, and 11,000 smaller plants. The vegetation will create a microclimate that supports birds, butterflies, and other insects, while also absorbing dust — a serious problem in Milan — and CO2, linked to climate change. It will also cut noise pollution and conserve energy.

As growing urban populations strain available space, the idea is to expand upward rather than outward. Though questions remain, Bosco Verticale provides a glimpse of a future where skyscrapers might one day double as forests.

Solar Trees in Singapore

With environmental awareness on the rise among its youthful population, this clean-cut, high-tech city is emerging as the green capital of Asia. Witness the new Gardens by the Bay, an ambitious renewable energy project and ecotourism attraction set on 250 acres of reclaimed land, offering a greener vision of urban renewal.

It features 18 solar-powered “supertrees” up to 16 stories tall, made from steel and concrete “trunks” covered in thousands of plants. Two massive, futuristic-looking glass conservatories capture and filter rainwater. Inside is a Noah’s ark of some of the world’s plants, including, for visitors, interpretations of their modern and traditional uses.

Carbon-sucking spree in Chicago

The famous Millennium Park — surrounded by trendy restaurants and filled with trees and flowers — is actually the largest green roof in the world, stretching some 25 acres over a bustling underground commuter rail station and parking garages. It forms the heart of Chicago’s green belt (which covers roughly 17 percent of the metropolis and removes more than 25,000 tons of greenhouse gases from the air annually).

The past several years under Mayor Rahm Emanuel and his predecessor Richard M. Daley have seen the city shutter two smog-creating coal-fired power plants that rained pollution onto low-income neighborhoods, call for all new buildings to meet

, invest in 100 miles of bikeways, and make plans for replacement of 900 miles of leaky city water pipes.

Trash to Treasure in Sydney

Australia’s first regional food-waste-to-energy power plant, EarthPower can convert over 80,000 tons of food waste each year into renewable energy.

An anaerobic process transforms nearly one-third of the city’s discarded leftovers (think of the restaurant scraps alone). The results are a biogas that helps power the metropolitan area’s electrical grid and the prevention of food rubbish from rotting in landfills and producing methane — a large contributor to global warming.

Electricity-Making Sidewalks in London

Sidewalk slabs — made from old car tires — that generate electricity from the pressure of a footstep, harnessing the kinetic energy of walking to power streetlights and other electronics?

During last year’s Olympic Games, temporary slabs made enough energy to light up the walkway between the Tube station and the stadium each night. They are now being installed permanently at the Westfield Stratford City shopping center near the Olympic Stadium. Airports could be next, capturing the frantic energy of travelers as they rush to catch their flights.

The Bottom Line

“Things that were unimaginable just a few years ago are now possible,” says Jeffrey Sachs, director of Columbia University’s Earth Institute. But he also warns that time is running out. “I believe we have maybe two generations to embrace the technologies that allow us the benefits of modern life while sustaining the planet.”

That’s roughly 50 years. Not a long time, but who would have imagined even a decade ago the apiary that now produces local honey atop New York’s Whitney Museum of American Art? I can see a day when city dwellers will take an elevator to the 27th floor to buy organic vegetables from skyscraper farmers using compost to help power the building—and lifting us closer to a sustainable future.

Comments

Paola pace

Italy

July 25, 2014, 4:21 am

Copenhagen is an amazing city in regard to sustainability.
It uses its garbage to produce house heating,it has miles of cycling paths which incurage people to cycle to work, to visit friends,for nights out,to visit the city if you are a tourist. There is an efficient system to filter the water of the canals and the port which appears clear so allows people to swim in it.
The project of the new port is so well done that brings people near the sea at all times. The long cycling path runs along the brim of water so that one feels as if touching it with the wide and bright view in front of you. Looking out a sea one cannot miss the modern wind powered energy makers.
Although there is a very old and fascinating part of the town, this city is making good effort to keep a low profile regarding the human impact on this earth!